1. Field of the Invention
The present invention relates to a medical needle device for use in medical procedures and, more particularly, a reusable unit dose needle device having a disposable needle assembly.
2. Description of Related Art
Disposable medical devices with piercing elements are well-known for administering medications such as a vaccine or withdrawing fluid from the human body. Such devices include hypodermic needles, blood collecting needles, fluid handling needles, and needles used in the administration of vaccines. These devices require safe and convenient handling to minimize exposure to bloodborne pathogens. Typically, disposable medical devices are discarded in their entirety. For example, numerous devices have shielding mechanisms for shielding the needle cannula after use. Many of these devices are complex to use and costly to manufacture. In addition, the disposal of the entire device is inefficient and costly.
One application for such a device is in the administration of vaccines or other active pharmaceutical ingredients that are applied through the skin. Bifurcated or forked-end needles are well-known for providing a simple and effective means for a medical practitioner to administer a vaccine. During use, the bifurcated tip of the bifurcated needle is placed into contact with either a dried or liquid substance, which adheres to the bifurcated needle tip. The bifurcated needle tip is then placed into contact with the skin of the patient. The skin is either scratched or pierced with the needle tip so that the vaccination material may be absorbed into the skin of the patient. An alternative method of delivering the vaccine includes placing a drop of the vaccine onto the skin of the patient and piercing the skin with the bifurcated needle tip through a drop of the vaccine. A standard pointed needle tip may also be used when the drop of vaccine is applied directly to the skin of the patient.
The bifurcated needle is considered a significant medical advancement because it allows more people to be vaccinated with less serum. This has been especially important for those living in less developed areas because of the efficient and easy to use design, as well as the ease of replication. Vaccination effectiveness, however, is reduced if the bifurcated needle is reused too many times. More importantly, reuse of such vaccination needles exposes patients to the risk of transmission of infectious diseases through percutaneous contact through the skin.
Additionally, medical care workers using traditional vaccine needles are at an increased risk of exposure to infectious disease due to the design of such needles, which makes them difficult to handle. In particular, bifurcated needles used to administer vaccinations are not traditionally sterilized or packaged in a single-use container that would enable convenient storage and use. Such needles have traditionally been difficult to handle because they typically do not include a hub attached to the opposite end of the needle tip, and typically do not include any sort of holder for carrying the needle cannula prior to use or any sort of shielding for covering the needle tip after use.
In view of the foregoing, a need exists for a reusable medical needle device in which a disposable needle and hub assembly may be used. A specific need exists for a reusable medical needle device that is capable of carrying a bifurcated needle and hub assembly that is quickly and easily disposable after use, such as after use in a vaccination procedure.
The above needs are satisfied with a medical needle device made in accordance with the present invention. The medical needle device includes a holder, a needle assembly, and an ejector rod cooperating with the holder. The holder has a proximal end and a distal end, and defines an opening extending from the proximal end to the distal end. The distal end has a socket for receiving a needle hub. The needle assembly includes a needle hub and a needle. The needle hub is received in the socket. The ejector rod extends into the opening from the proximal end of the holder. The ejector rod is slidably received in the holder and has a distal end configured to communicate with the needle hub. The ejector rod has a proximal end extending outward from the holder. Movement of the ejector rod into the holder causes the distal end of the ejector rod to bias the needle hub outward from the socket, thereby ejecting the needle assembly from the holder. Desirably, the needle is a bifurcated needle, and is connected to the hub by a medical grade adhesive. A proximal end of the needle hub may define a luer cavity.
The holder may define an internal rib extending into the opening. A bushing is adjacent the distal end of the ejector rod, and may be received about the distal end of the ejector rod between the needle hub and internal rib. Preferably, the needle hub and the socket are in threaded engagement. The bushing may have an outer diameter small enough to prevent threaded engagement with the threads of the socket, such that movement of the ejector rod into the holder causes the bushing to come into rotational contact with the needle hub, thereby unthreading the needle hub from the socket and ejecting the needle assembly from the holder. Also, a spring may be received about the ejector rod and located on an opposite side of the internal rib from the bushing for biasing the ejector rod outward from the proximal end of the holder.
In a further embodiment, the present invention includes a holder for a disposable medical needle assembly. The holder includes an elongated holder body, an ejector rod cooperating with the holder body, a bushing received about the ejector rod, and a spring also received about the injector rod. The holder body includes a proximal end and a distal end, and defines an opening extending from the proximal end to the distal end. The distal end of the holder has a socket for receiving needle hub. The holder body defines an internal rib extending into the opening. The ejector rod extends into the opening from the proximal end of the holder body. The ejector rod is slidably received in the holder and has a distal end extending into the holder body. The ejector rod has a proximal end extending outward from the holder body. The bushing is received about the ejector rod and is located on a side of the internal rib facing the distal end of the holder body. The spring is received about the ejector rod and is located on an opposite side of the internal rib from the bushing for biasing the ejector rod outwardly from the proximal end of the holder body.
The holder may further include a button enclosing the proximal end of the ejector rod. The button may have a spring engaging end located within the holder for compressing the spring within the holder. Movement of the button into the holder may cause the ejector rod to contact the bushing such that the bushing comes into rotational contact with the needle hub and forcing the needle hub outward from the socket, thereby ejecting the needle assembly from the holder.
Further, an alternate embodiment of the medical needle device having a disposable needle assembly includes a holder, a needle assembly, an injector rod cooperating with the holder, a spring received about the ejector rod, and a button for operating the ejector rod. The button encloses the proximal end of the ejector rod and has a spring engaging end located within the holder for compressing the spring within the holder. Movement of the button into the holder causes the distal end of the ejector rod to force the needle hub outward from the socket, thereby ejecting the needle assembly from the holder.
Further details and advantages of the present invention will become apparent from the following detailed description read in conjunction with the drawings.